Blast-controlling device for dental or other uses.



No. 742,305. PATENTED OCT. 27, 1903. N. K. GARHART. BLAST GONTROLLING DEVICE FOR DENTAL OR OTHER USES. APPLIOATION FILED APR. 17, 190s. No MQDL.

@Moenia lll".

UNTTnn STATES Patented october 2v, 190s'.

PATENT Cerros.,

GARIIART DENTAL MANUFACTURING COMPANY,

OF INDIANAPOLIS,

INDIANA, A CORPORATION OF INDIANA.

BLAST-CONTROLLING DEVICE FOR DENTAL OR OTHER USES.

SPECIFICATIQN forming part of Letters latent No. 742,305, dated October 27, 1903.

Serial No. 153,034. (No model.)

To @ZZ whom t may concorre:

Be it known that I, NATHAN KLINE Grin- HART,a citizen of the United States,residing at Indianapolis,in the countyofMarion and State 5 of Indiana, haveinvented certain new and use ful Improvements in Blast-Controlling Devices for Dental or other Uses, of which the following is a specification.

This invention is designed to provide for ro the convenient control of a blast of air and for the changing of thesame at will from cold to hot or from hot to cold. It is especially useful in dental Work where it is desired to supply asuitable small blast of air for the purpose of drying cavities and the like and also for blowing away the fine particles resulting from drilling and other mechanical operations.

An apparatus embodying said invention zo will be first fully described and the novel features thereof then pointed out in the claims.

Referring to the accompanying drawingsl which are made a part hereof and on which similar reference characters indicate similar parts, Figurel is a side elevation of an apparatus embodying said invention with fragments of the air-supplying tube and of the electrical line-wires attached thereto; Figs. 2 and 3, central longitudinal sectional views 3o thereof; Figs. e, 5, and 6, transverse sectional views on the dotted lines l Ll, 5 5, and 6 6, respectively, Fig; 6 being on an enlarged scale; Fig. 7, a detail view similar to a portion of Fig. 2, but on an enlarged scale; and Fig. 8,

a detail plan view at the valve-point with the shield broken away.

This instrument is composed of a tubular body or main portion 2l, made of insulating material, a nozzle 22, vleading therefrom, a

4o heating or resistance coil 24, contained therein, and an operating-lever 25. The ends of the heating or resistance coil are connected to conductors 3l and 32, which lead back through the body of the structure to the binding-posts 33 and 3e and are there connected to the line-wires 35 and 36, which lead from any suitable source of electrical energy. (Not shown.) One of the conductors 3i is in` terrupted, one of the parts terminating in the 5o contact-point 37 and the other in a bindingscrew 3S, to which I also prefer to connect a spring 39,which will form a part of the conductor when the circuit is completed. This spring also serves the further purpose of holding the lever 25 outwardly. The circuit is made, as 55 will be readily understood, by pressing down on the lever until either the spring or thelever strikes the contact 37. The circuit is broken by the action of the spring itself when pressure on the lever is released. Pressing the 6o lever down until this contact is made, therefore, will throw an electrical current through the heating or resistance coil, which is Within the passage through which the air flows and is thus the means for heating the air. The lever 25 is most conveniently mounted on the body 2l of the instrument by means of pivotscrews 2G. The other end of the lever extends bacl; over and serves to operate the air-valve. This air valve I prefer to con- 7o struct in the following manner: I shut olf the orifice through the body 2l of the instrument at an appropriate point and lead out a suitable escape-opening toward the side thereof, terminating in a valve-seat 27. In the side of said body I make a chamber, and from this chamber a perforation 28 leads back into the longitudinal opening in the body of the instrument. I then preferably form a circumferential recess in the body of the instrument 8o and rst lay into this, covering the chamber, a piece of thin flexible fabric el, such as rubber or'leather, which is adapted to be pressed down tightly onto the valve-seat surrounding the orifice leading out into the chamber and to close the iiow of air when desired. The valve-closing end of lever 25 is directly over this orifice. I slip over` the flexible material a tubular metal shield e2, having an opening through which the valve-operating 9o end of the lever 25 can work. By means of a screw e3 I draw this shield tightly down onto the leather, making an air-tight connection around over the chamber in the body of the instrument. Nhen the lever is at rest, it (operated by the spring 39) will pass down on this soft iexible material, which serves as the air-valve and keeps the orice closed. Vhen the other end of the lever is pressed down and force thus removed from the flexiroo ble material, the pressure of air beneath will force it up off the valve-seat, permitting the air to flow into the chamber in the body of the instrument, and thence through the perforation described out toward the heatingchamber and the discharging end of the instrument. In order that this flexible material shall not have a tendency to stick'to the Valve, I mount in or around the oriiice a small coiled spring 4A.

ln operation I proceed as follows: The air is supplied from any ordinary or convenient source, as through a flexible tube 5l. Its pressure, however, is not sufficient to overcome the pressure of the spring-operated lever on the valve. When, however, the lever is pressed down slightly, the air will flow through, as has been described. The lever need not (for this purpose) be pressed down far enough to make the electrical contact described. So long as the lever is held in an intermediate position there will be a flow of cold air of the temperature at the source of supply. When, however, it is desired to heat the air, it is pressed down a little farther' until the. electrical contact is made, when the heating or resistance coil will come into operation and heat it, as will be readily understood. There is no danger of leaving the heating-coil in operation after the air is shut off, as the first movement of the lever upwardly under the force of the spring breaks the electrical contact, so that the current of electricity is shut off before the supply ef air is shut off. This is of great advantage, as were it otherwise great care would have te be taken else the delicate resistance-coil employed for this work would be in danger of being burned out. As I have it arranged, the air necessarily is flowing through it and carrying away the heat as long as the circuit remains unbroken.

Having thus fully described my said in vention, what l claim as new, and desire to secure by Letters Patent, is

l. A dental tool consisting of a hollow body capable of use in one hand, an electric heating-coil mounted therein, a valve controlling the passage through said body and the coil, a switch forming part of the coil-circuit, and a swinging finger-lever for operating both the valve and the switch, for the purpose set forth.

2. In a dental tool, the combination of a hollow body, a valve in the passage thereof consisting of a flexible membrane arranged above an orifice within a chamber, means for holding said membrane tightly around the edges of said chamber, a lever whose end is arranged above the valve-seat and adapted to press the membrane down onto said seat and close the valve, and a spring whereby said lever is operated to hold the valve in closed position, substantially as set forth.

3. In a dental tool, the combination of a tube containing a chamber, a valve-seat in said chamber, a flexible valve over said valveseat, a spring-pressed closer for said Valve, and a spring below said flexible valve for raising the saine when the pressure on the closer is released.

e. A dental hand-tool consisting of a noncouducting body having a valved air-passage therethrough, the said valve, an electric heating-coil carried by said body at its forward end and connecting with the airpassage thereof, the circuit-wires therefor, a switch forming part of said circuit, a nozzle at the forward end of said coil and a swinging finger-lever for operating the valve and the switch, substantially as and for the purpose set forth.

ln witness whereof l have hereunto set my hand and seal, at Indianapolis, Indiana, this 13th day of April, A. D. 1903.

NATHAN KLINE GA ltliA li'l.

lh Sil 

